Electrical connectors having a plurality of socket-type contacts encapsulated within a molded body are well known. For example, co-pending U.S. patent application Ser. Nos. 08/134,075 U.S. Pat. No. 5,387,119 titled Waterproof Electrical Connector, and 08/226,009 U.S. Pat. No. 5,470,248 titled Field Repairable Electrical Connector, filed respectively on Oct. 8, 1993 and Apr. 11, 1994 by the inventor of the subject matter claimed herein, disclose electrical connectors formed by injection molding a nonconductive plastic material around a plurality of contact sockets arranged in a preselected pattern.
Heretofore, there have been two major problems associated with the prepositioning of the contacts and molding of the connector. The first difficulty is attributable to the very small tolerances, typically about 0.001 inch (0.025 mm), that must be maintained to assure mating alignment of the sockets with the pins that are subsequently inserted into the socket contacts to form an electrical connection. The contact pins may have a very small diameter, for example about 0.040 inch (0.1 mm) or less, and can be easily bent during insertion into the receiving socket if not properly aligned. Electrical connectors of this type may contain 30 or more individual contacts, and even with the aid of keys and keyways provided in mating portions of connectors, providing perfect alignment of all the pins and their respective mating sockets has been a continuing and consistently difficult challenge to the manufacturers of such connectors.
Secondly, it has been difficult to prevent the intrusion of nonconductive material into the interior of the socket of the contact during molding of the connector. Typically, the connectors are formed by high pressure injection molding of a molten plastic around the sockets which are prepositioned in a mold cavity. Often, the socket contacts have one or more lateral openings in the side wall of the socket as a result of forming spring contacts in the socket wall to assure good electrical connection with a mating pin. To prevent intrusion of molten plastic through the sidewall opening, covering sleeves have been installed over outer surface of the socket prior to molding. This arrangement has been successful in preventing sidewall intrusion of nonconductive material into the socket, but has not solved the problem of intrusion of molten material into the open end of the socket. The use of temporary plugs and mold pins to seal over the open end of the socket contact has been only partially successful due, in large measure, to the critical accuracy to which such blocking members must be positioned and maintained in order to be perfectly aligned with the small opening.
The present invention is directed to overcoming the problems set forth above. It is desirable to have an electrical contact assembly that provides an enlarged "target" area for a mating pin, and then guide the pin into the socket during insertion. It is also desirable to have such an electrical contact assembly that prevents intrusion of nonconductive material into the socket opening during molding of a connector assembly.